A speed governor controls and adjusts the speed of an engine typically by controlling the amount of fuel supplied to the engine during operation. If the engine is to run at a faster speed more fuel is supplied, whilst less fuel is supplied if the engine speed is to be reduced. Governors are key components of engine control systems, particularly as engine manufacturers seek to develop more efficient engines.
In engine control systems, governors usually receive control signals from an engine controller. Engine controllers monitor numerous input and output parameters of an engine in order to ensure optimum performance of the engine. With the drive towards more and more efficient and economical engines, engine controllers are often now tasked with ensuring that engines are performing at optimum efficiency. This typically involves the engine controller being provided with one or more engine maps to ensure that the engine is operating as efficiently as possible. For example, the engine map may be a map of engine power versus engine speed to ensure that the engine produces a certain engine power at the lowest possible engine speed. The controller can then instruct the governor to adjust the engine speed so that the engine speed remains as low as possible for the required power, as defined by the engine map.
Whilst such control arrangements can improve the efficiency of an engine they have limitations when applied to engines in vehicles which have engine-powered ancillary systems and components, for example. In such vehicles demand for increased engine power from, for example, a hydraulic circuit controlling a tipper bed or bucket can lead to a delay in the increased power being delivered as the engine controller reacts to the demand. It can also mean that the efficiency of the engine is compromised as the controller tries to meet the twin targets of the engine efficiency map and the increased power demanded by the ancillary systems.
It is an aim of the present invention to obviate or mitigate this and other disadvantages with existing engine control systems and/or processes.